/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 666
 * Date: 2022-11-29
 * Time: 23:09
 */
import java.util.Scanner;

 class Main1 {
    public static boolean checksum(long a){
        long end=a%10;
        a=a/10;
        long b=0;
        long c=0;
        long a1=a;
        while(a1>0){
            b+=(a1%10);
            a1/=100;
        }
        b*=7;
        a1=a;
        a1/=a1;
        while(a1>0){
            c+=a1%10;
            a1/=100;
        }
        c*=2;
        b+=c;
        b%=10;
        if(b==end)
            return true;
        return false;
    }
    public static void main1(String[] args) {
        Scanner in = new Scanner(System.in);
        long code = in.nextLong();

        boolean checksumResult = checksum(code);
        if (checksumResult)
            System.out.println("The checksum of "+code+" is "+ "correct");
        else
            System.out.println("The checksum of "+code+" is "+ "incorrect");
    }
}
